The present invention relates to an improved separated-unit type air conditioner, in which the compressor, the heat exchangers, the air blowing devices, and the expansion valves are suitably and separately provided in an indoor unit and an outdoor unit, and a remote controller for these units is provided at a location different from those of the indoor and outdoor units.
A conventional air conditioner of this general type is shown in FIG. 1. In FIG. 1, reference numeral 1 designates an indoor unit, 10 an outdoor unit, 20 a remote controller, 101 a three-phase (or single-phase) electric power line coupled to the indoor unit, 102 a three-phase (or single-phase) electric power line coupled to the outdoor unit, 103 control signal lines extending between the indoor unit 1 and the remote controller 20, 104 control signal lines between the indoor unit 1 and the outdoor unit 10, and 105 refrigerant piping extending between the indoor unit and the outdoor unit.
In general, in the conventional air conditioner, a number of control signal lines 103 are laid between an electronic controller (not shown) including a microcomputer provided in the indoor unit and the remote controller 20 including various operating switches, keys and light emitting elements for display. In addition, a number of control-signal lines 104 are connected between the indoor unit and the outdoor unit which are used to control a compressor, an air blower and various operating valves (not shown) in the outdoor unit using the outputs of the electronic controller in the indoor unit, and to input the signals of a temperature control thermostat and various protecting device (not shown) in the outdoor unit to the electronic controller in the indoor unit. A multiconductor cable having ten to twenty conductors is employed for the control signal lines 103, and a multiconductor cable having five to ten conductors is employed for the control signal lines 104.
However, appropriate multiconductor cables, especially the multiconductor cable having ten to twenty conductors used as the control signal lines 103, are not readily available commercially. Even if a multiconductor cable is available, the presence of the multiconductor cable may be rather unsightly. The appearance of the house or room may be maintained unchanged by locating the cable in the walls of the house. However, in this case, it is difficult to insert the cable into a conduit tube, and accordingly the entire wiring operation is considerably difficult. In addition, the employment of the multiconductor cable for the control signal lines 104 increases the time required for the installation and is liable to cause errors in the wiring since it is laid between the indoor unit and the outdoor unit.
Furthermore, the conventional air conditioner is disadvantageous in that, where a sensor (not shown) is added to the outdoor unit in order to save energy or to control the air conditioner so that the occupants of the room feel comfortable at all times, it is necessary to increase the number of control signal lines 104.